magpie.utility

Class UtilityOperations

java.lang.Object

magpie.utility.UtilityOperations

public class UtilityOperations
extends java.lang.Object

This is only a class full of useful static methods.

Constructor Summary

Constructors

Constructor and Description
UtilityOperations()

Method Summary

Modifier and Type	Method and Description
static java.io.File	findFile(java.lang.String toFind) Given the path of a path relative to the Magpie jar, find the actual path.
static boolean	isInteger(java.lang.String str) Determine whether a string represents an integer.
static java.lang.Object	loadState(java.io.InputStream input) Read in a Magpie object from a stream
static java.lang.Object	loadState(java.lang.String filename) Read the state from file using serialization
static java.lang.String	millisecondsToString(long time) Print a time, stored in milliseconds, into a human-readable string.
static <T> java.util.List<java.util.List<T>>	partitionList(java.util.List<T> toSplit, int nPartitions) Split a list into smaller sublists that are as equally-sized as possible.
static void	printRunTime(long start_time) Print elapsed time to screen
static void	saveState(java.lang.Object obj, java.io.OutputStream output) Use serialization to save object state to an output stream
static void	saveState(java.lang.Object obj, java.lang.String filename) Use serialization to save object state to file
static int[]	sortAndGetRanks(double[] x, boolean descending) Sort an array and return the original indices of the each value.
static int[]	sortAndGetRanks(double[] x, java.util.Comparator<java.lang.Double> comp) Sort an array and return the original index of each member.
static org.json.JSONArray	toJSONArray(double[] array) Convert an array of doubles into a JSON array.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

UtilityOperations

public UtilityOperations()

Method Detail

loadState

public static java.lang.Object loadState(java.lang.String filename)
                                  throws java.lang.Exception

Read the state from file using serialization

Parameters:

filename - Filename for input

Returns:

Object stored in that file

Throws:

java.lang.Exception

loadState

public static java.lang.Object loadState(java.io.InputStream input)
                                  throws java.io.IOException,
                                         java.lang.ClassNotFoundException

Read in a Magpie object from a stream

Parameters:

input - Input stream

Returns:

Object stored in the stream

Throws:

java.io.IOException

java.lang.ClassNotFoundException

saveState

public static void saveState(java.lang.Object obj,
                             java.lang.String filename)
                      throws java.io.IOException

Use serialization to save object state to file

Parameters:

obj - Object to be serialized and saved

filename - Desired filename

Throws:

java.io.IOException

saveState

public static void saveState(java.lang.Object obj,
                             java.io.OutputStream output)
                      throws java.io.IOException

Use serialization to save object state to an output stream

Parameters:

obj - Output

output - Output stream

Throws:

java.io.IOException

printRunTime

public static void printRunTime(long start_time)

Print elapsed time to screen

Parameters:

start_time - When operation started (as reported by System.currentTimeMillis())

isInteger

public static boolean isInteger(java.lang.String str)

Determine whether a string represents an integer. Thanks to StackOverflow

Parameters:

str - String containing a single word

Returns:

Whether string represents an integer

findFile

public static java.io.File findFile(java.lang.String toFind)

Given the path of a path relative to the Magpie jar, find the actual path.

Parameters:

toFind - Relative path to file or directory (e.g. "py/lasso.py")

Returns:

Path to file. null if not found

partitionList

public static <T> java.util.List<java.util.List<T>> partitionList(java.util.List<T> toSplit,
                                                                  int nPartitions)

Split a list into smaller sublists that are as equally-sized as possible.

Parameters:

toSplit - List to be split

nPartitions - Number of partitions to create

Returns:

List of sublists

toJSONArray

public static org.json.JSONArray toJSONArray(double[] array)

Convert an array of doubles into a JSON array.

Changes in NaN or inf values into strings (JSON doesn't support these as numbers

Parameters:

array - Array to be converted

Returns:

Array as JSON

millisecondsToString

public static java.lang.String millisecondsToString(long time)

Print a time, stored in milliseconds, into a human-readable string.

Parameters:

time - Time in milliseconds

Returns:

Time as a human readable string

sortAndGetRanks

public static int[] sortAndGetRanks(double[] x,
                                    boolean descending)

Sort an array and return the original indices of the each value.

Parameters:

x - Array to be sorted

descending - Whether to sort the list in descending order

Returns:

List of indices, sorted in same order as x

sortAndGetRanks

public static int[] sortAndGetRanks(double[] x,
                                    java.util.Comparator<java.lang.Double> comp)

Sort an array and return the original index of each member. After operation, x will be sorted.

Parameters:

x - Array to be sorted

comp - How to compare entries in the array

Returns:

Original index of each point